, some crime like that taking place he. >> reporter: police say this man used the internet to befriend a woman whom he later held captive and victimized. >> the person may seem like a nic person on the other end of the phone. if you don't know them, you have to assume that foul play could be involved. >> reporter: accoing to the sheriff, this go back to june. that's when they stay suspect john swan evanset the victim on the dating website eharmony.com. july, they say, he lured her to his house here in south riding. and health her against her will. and sexually assaulted her here. there is fear there could be more vicms. >> in a situation like this, the same as someone has been scammed them don't want the embarrassment of someone being scammedo they don't say anything. that'sow these perpetrators continuing. if anybody is fwam this person, we would lake to hear from them. >> reporter: some advice fom the sheriff. when you go to meet someone for the first time, don't do it at their place or your place. do it in a public place. it's mu safer there. i'm pat collins, news4, loudoun county.